1. Field of the Invention
The present invention relates to an anode containing silicon (Si) as an element, a battery using it, and a method of manufacturing an anode.
2. Description of the Related Art
In recent years, as mobile devices have been sophisticated and multi-functionalized, a higher capacity of secondary batteries as a power source for these mobile devices has been demanded. As a secondary battery to meet such a demand, there is a lithium ion secondary battery. However, since the lithium ion secondary battery currently in practical use utilizes graphite for the anode, the battery capacity is in a saturated state and attaining a significantly high capacity thereof is difficult. Therefore, it has been considered to use silicon or the like for the anode. In recent years, forming the anode active material layer on the anode current collector by vapor-phase deposition method or the like has been reported (for example, refer to Japanese Unexamined Patent Application Publication No. H08-50922, Japanese Patent Publication No. 2948205, and Japanese Unexamined Patent Application Publication No. H11-135115). Since silicon or the like is largely expanded and shrunk due to charge and discharge, lowering of cycle characteristics due to pulverization has been a problem. However, when the vapor-phase deposition method is used, miniaturization can be inhibited, and the anode current collector and the anode active material layer can be integrated. Therefore, electron conductivity in the anode becomes significantly favorable, and realizing high performance in view of the capacity and the cycle life has been improved.